Tuning of spin-transfer torque in VSe2-based vdW magnetic tunnel junctions by electrode polytypes

Inspired by the promising properties of monolayer 1T-VSe 2 , known for its ferromagnetic ordering and room-temperature Curie point, we developed a 2D van der Waals heterostructure featuring 1T-VSe 2 as the ferromagnetic layer, non-magnetic semi-infinite 1T- and 2H-TaS 2 electrodes, and 2H-MoS 2 as the tunneling barrier. Employing ab initio quantum transport simulations within the nonequilibrium Green’s function framework, we explored the impact of TaS 2 electrode polytypes on the device’s quantum transport properties. Devices with 1T-TaS 2 electrodes exhibit higher spin-dependent transmission compared to 2H-TaS 2 . Incorporating 2H-MoS 2 enhances anisotropic tunnel magnetoresistance, reaching 168% for the 1T-device and 1419% for the 2H-device, peaking when 1T-VSe 2 magnetizations are antiparallel. Spin-transfer torque magnitude is highest at 90° and decreases towards 180°. 1T-device shows superior performance with lower Gilbert damping, and reduced critical current density and voltage for magnetization switching, compared to the 2H-device, which requires significantly higher current and voltage. These findings underscore the potential of 1T-VSe 2 -based heterostructures in spintronics.